Process for treating hydrocarbon oils



- No Drawing.

Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE ARTHUR LAZAR, OI ASSOCIATED, CALII'ORN IA, ASSIGNOB TO ASSOCIATED OIL COMPANY, OF SAN FRANCISCO, CALIFORNIA,

A CORPORATION OF CALIFORNIA PROCESS FOR TREATING HYDROCAR-BON OILS This invention relates to an improved process for treating hydrocarbon oils to produced an oil with new and valuable characteristics.

Stability towards oxidation and thermal decomposition are characteristics very desirable in oils such as those used in transformers, turbines and in internal combustion engines.

It is therefore the object of this invention to treat certain distillate fractions in such a manner that the product resulting therefrom exhibits a vast improvement in the desired characteristics. This process consists essentially in the treatment of lubricating distillates and the like with a selective solvent, redistilling or reducing the oil, with or without previous neutralization, to attain the desired physical characteristics, and the particular manner in which the adsorbent material is utilized-for decolorizing and re moving other impurities.

Heretofore, in the production of such oils it has been the general ractice among refiners to select distillate f i'actions of the approximate physical characteristics desired, reducing the distillate until the oil has the proper viscosity or flash; then subjecting the distillate to the usual acid treatment, and after neutralizing with a caustic solution, treating with some adsorbent material such as clay to remove decolorizing matter and other impurites. It has been found that oils of certain origin produced in this manner, especially the lubricating oils, do not show sufiicient stability toward oxidation and thermal decomposition.

Inrthe treatment'which is the subject of this invention, certain hydrocarbon fractions are selected whose physical characteristics most nearly approach those desired in the finished oi These fractions are then treated with a selective solvent, in which the unsaturated and aromatic compounds are dissolved and then are removed by gravity separation. The undissolved portion, the so-called raflinate is then reduced to the desired viscosity and flash and the reducedvoil treated with an adsorbent decolorizing material. It is essential Application filed December 17, 1927. Serial No. 240,931.

to maintain the sequence of operations as described in order to obtain finished products of high qualities. It has been found that when reduction of the oil is carried out prior to. the treatment with the selective solvent,

certain hydrocarbons break down under heat 55 into forms in which they are objectionable in the lubricant but not soluble in the selective solvent later. On the other hand, if the unreduced hydrocarbon oil is first treated'with a selective solvent, the components which are liable to break down and form the objectionable and insoluble hydrocarbons mentioned before, are removed and only those of a more stable nature remain during the reduction which follows. It is of importance to note that the same lubricating stocks treated bythe same operations but in a different sequence as described by carrying out the reduction before the treatment with the selective solvent will show much inferior qualities in use. Furthermore, it can be proved that mere laboratory testing is not sufiicient for characterizing the real value of oils which have to perform under severe condi-tions, as, for example, in an internal combustion engine. The two products processed by the same operations but in a different sequence of the individual steps usually will show very similar physical properties. Upon more thorough tests of performance under the most severe conditions in a stationary internal combustion engine and in road tests, the oil processed in the proper sequence of operations as described above will perform much better than the one which had been reduced previous to the treatment with the selective solvent. The latter one, submitted to a test run in the motor shows high consumption, high carbon deposition and gummy or resinous deposits on the movingv parts of the engine, whereas the product obtained by the proper method'treating with the selective solvent, reducing after the treatment and decolorizing the reduced oil will be found to be an excellent lubricant.

Of all the substances which show selective dissolving properties of hydrocarbon oils, liquid sulphur dioxide is known to be the' most suitable and eflecti e' As far as the loo treatment with this solvent is concerned, the treated oil naturally is bound to show a slight acidity due to traces of the solvent retained in the so-called rafiinate. In the majority of cases this slight acid reaction might eteriorate the color of the bottoms during the following reduction and also endan er the reducing equipment by corrosion. .or this reason, a neutralization previous to the reduction is advisable. It might be mentioned that this neutralization has no effect at all on the internal qualities of the finished product but is only recommended for getting a good final color. As neutralizing agents, all

kinds of chemicals either in solid form, can be used, the ind of chemical andmanner of application depending chiefly on the equipment available- It is also possible to carry out the reduction in the resence of the neutralizing agent. As suita le neutralizing agents may be mentioned ammonia in gaseous form or solution, the oxides and gaseous, liquid or hydroxides of the alkaline earth metals, aluminum oxide and hydroxide and other adsorbent materials like clay. Those latter ones not only act as neutralizing agents but also have a high adsorptive power for colored materials, thus combining a considerable de- -vious to the reduction,

, to cut down the amount of adsorbent clay to be applied to the reduced oil in the last ste colorizing efiect with the neutralizing action.

It is evident that the use of such kinds of adsorptive materials for neutralization, prewill make it possible of the rocess as heretofore described.

Having now more articularly this invention, the app ication of this process should only be restricted and. hereinafter appended claims.

What I claim is:

1. The process of treating hydrocarbon oils which comprises treating the lubricating fractions with liquid sulphur dioxide, separatin the undissolved ortion from the dissolve portion, and reucing by distillation the undissolved portion in the presence of an adsorbent decolorizing material.

2. The process of treating hydrocarbon oils which comprises treating the lubricating fractions with liquid sulphur dioxide, separating the undissolved portion from the dissolved portion, reducing by distillation the undissolved portion in t e presence of an addescribed defined by the fractions with liquid sulphur dioxide, se aratin the undissolved portion from the issolve portion, reducing by distillation the undisso ved portion in the presence of a the same character.

' ARTHUR LAZAR.

sorbent decolorizing material, and removing the adsorbent materlal.

3. The process of treating hydrocarbon oils which comprises treatin lubricating fractions with liquid sulphur dioxide, se aratin the undissolved ortion from the issolve (portion, and re ucinfi by distillation the un issolved portion in t neutralizing and decolorizing adsorbent material.

4. The process of ,treating h drocarbon oils which comprises treating ubricating e presence of a 

